But it's a much less hard problem to make synthetic versions of them (eg butanol). And ultimately, sustainably.
This isn't actually true, and gets said a lot more than it really should.
This same argument was made for EVs, and here we a short time later, and it turns out that EVs are much more efficient as was predicted by nerds who did the sums before it was practical as a business.
But, you'll say, what about trucks or busses, they need much more fuel and therefore it's still all about energy density?
And I'll say, no, electric busses and trucks are being rolled out right now, because they are cheaper than diesel busses. Because they are more efficient.
Okay, but what about planes, you can't make an electric plane can you, so it's all about the energy density.
Except people are making electric planes, and their pitch is that they're going to be cheaper, because they're more efficient.
We could do shipping etc. but I think you get the point, so we'll skip to:
Wait, you say, really long distance flight that's not possibly with heavy batteries is it, so I'm still right.
Well, no, because you were attaching some magical properties to a fuel that we semi-randomly use today because we found a bunch of it lying around and didn't have anything better.
If kerosene didn't exist, and you had the tech to make it (which we do) why would you make it? Well, it's got the most energy density, right. Except methane and hydrogen score higher on gravametric energy density, so you could make those instead.
But you say, those need cooled and pressurised, not realising that this disproves your own claim that the only thing that matters is energy density. It's the whole system efficiency and cost that matters, just like the familiar EV story.
We mostly use fossil fuels for historical path dependency lock-in reasons. We'll continue to use synthetic versions of them in jets for the same reason, nobody wants to redesign working planes just to save some energy on fuel.
But at some point, new planes, and new air transport systems, will get designed around what is actually the cheapest form of energy we have lying around, and avoiding the externalities of carbon, NOx, and high altitude condensation and they'll probably look quite different than they do today and energy density will be only one of many factors.
A neat anecdote to summarise this, there's a company making 19 seater jets that are electric. They asked a few people in the business, do you fly any planes that size, and they all said no. But one regional airline said, no we don't, but we used to fly planes of that size all the time. We switched because the fuel cost economics for short flights was worse than long flights. We changed what we did, flying further in bigger planes, for cost reasons. They're now attempting to go back to more smaller planes.
> Is there really a market for 19-seater electric aircraft?
> A few decades ago, 19-seater aircraft were very common. Since then, the large acquisition and maintenance cost of turboprop jet engines have made 19-seaters uneconomical. Whereas regional planes averaged at 20 seats in the 1980s, today they average 80 seats.
> Why don’t airlines fly as many 19-seaters anymore?
>When the engine cost-of-ownership can be the same for a 19-seater and a 70-seater, and engine wear is the same whether you fly a 100 km as a 1000 km route, flying short hops with small turboprop aircraft is simply not profitable to airlines.
> How does going electric change the economic equation?
> Our electric motor is about 20 times less expensive than a similarly-size turboprop, and about a 100 times less expensive than the cheapest turbofan. More importantly, maintenance costs are more than 100 times lower. These lower operating costs will make 19-seater electric aircraft competitive to 70-seater turboprop aircraft.
The ES-19 is propeller-driven, not a jet. Its no-reserve range is projected to be 250 miles. That may make for a suitable island-hopper, but is neither a jet nor a jet-substitute.
My two points that got kind of mashed together are:
1) that the current jets run on kerosene and will run on synthetic e-kerosene in the near future but if you have to synthesize the fuel from scratch anyway then long chain alcohols or methane or whatever will also be on the menu as potential fuels to synthesise, and we can evaluate them on multiple dimensions (toxic, volatile, cheap) to see what's best.
2) Once you throw the old paradigm out, there's no reason to expect the same thing to appear but electric/carbon neutral. An EV doesn't have to ape ICE cars in every respect, even though that was the initial reference point. It can be both better in some dimensions and worse in others, like iPads vs laptops. The reboot allows for some (re-)exploration of the design space of the whole transport system as well as the individual vehicles. Smaller cargo boats and planes will probably make more sense for the reasons given around low maintenance and fuel costs as well as increased automation. We know sythetic e-fuel jets are technically possible, but will they make business sense compared with something new?
Having just booked a train ticket this morning let me tell you a story.
Munich - Berlin, just shy of 600km, in a country that's supposed to be not completely shit in regards to train infrastructure (I personally disagree, but that's another topic).
It cost me 180 EUR and it's 2 times 4h. Because I need to be there at noon on my arrival day I basically only have the choice of 2 different trains, I really hope there's no problem. Oh, and I had to pay to reserve a seat. I don't remember ever having to stand in a plane.
Just for fun I actually asked for the flight price, which was... 140 EUR. 2 times 1h10 or something. (I know, I know, it's not completely realistic, but the airport is actually closer than the main station for me, probably 1:1 in terms of time to get there). (both prices incl. return, btw).
But the main problem? I don't trust Deutsche Bahn that I will arrive on time. Of course there are no proper overnighters anymore, just some "oh of course you can take a 9h trip in a seat where you will sit uncomfortably".
Of course, the reliability of Deutsche Bahn is another question.
However if you do want to book stuff months out, advanced purchase tickets are a staple of the airline industry. From Berlin you can get to a host of locations for about €20 each way, including Venice, Milan, Budapest, Madrid etc - far further than a domestic train.
It doesn't take away from your larger point, I understand.
> That wasn't incorrect. I'd rather put up with some jet lag than for all of my travel to take several times as long.
You just have different opinions. OP is claiming that, for them, taking half a week to travel 10.000kms is OK, should be the default and the rest of our lifestyle should accommodate that. And I tend to agree with them: it would be much cool to have 5-6 weeks holidays instead of 3 and spend 7/10 days to go and come back, which will be an enjoyable part of the holidays as well.
I get 30 days paid holiday per year. I could take all my holiday in one lump and spend 6 weeks travelling there and back. But I'd massively prefer to have more, shorter, holidays and not spend half my precious holiday time travelling.
And, obviously, I'm lucky. I work for a German company. When I worked in Australia the standard was 20 days, which makes a 10-day travelling time completely unworkable.
There are advantages to killing off bulk tourism, I'll agree. But I also don't think we want to go back to a world where only the idle rich get to travel.
> You just have different opinions.
That's my point. Others' opinions aren't incorrect just because they differ from your own.
Fun insight, thanks for that!
Flying is expensive enough that it's already not something that everyone does routinely. And once we get electric planes, then Earth will be able to afford that.
> we decided incorrectly that we needed to travel one time-zone per hour.
That wasn't incorrect. I'd rather put up with some jet lag than for all of my travel to take several times as long.